Homebrew Cray-1 Supercomputer Built In 1:10 Scale

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In 1976, Cray Research installed one of the most successful supercomputers of all time; the Cray-1. Capable of 160 million FLOPS (only matched by desktops 20 years later) the first of these 80 MHz giants sold for $8.8M. Utilising a staggering 32 MB of SRAM and performing 3 floating point operations per a cycle, this was the ultimate computer. The Cray-1 was designed to be fast and, as such, was heavily pipelined. As a result instruction execution time needed to be known in advance which lead to a RISC style architecture as opposed to x86′s CISC approach.

Fast forward to today and the numbers seem insignificant but there’s still something rather romantic about the Cray-1. Enter Chris Fenton with the dream of someday owning his own Cray-1. A freshly minted Electronic Engineer, Fenton opted to build his own Cray-1 using an FPGA kit, namely, the Xilinx Spartan-3E 1600 development board. It may not reach the spec of the original but it comes close without costing thousands of dollars.

Working with the Cray-1 Hardware Reference Manual he set about creating a binary-compatible, cycle accurate 1/10th scale Cray-1. Starting with the simpler arithmetic functional units Fenton worked his way up through the floating point units and on to implement the vector chaining that was fundamental to the Cray-1′s performance.

While it is not quite finished and it is rather short on RAM, Chris Fenton has produced one of the most inspiring home projects around, coining the term “computational necromancy” along the way; a term which we hope to hear again sometime soon. pWhile it is not quite finished and it is rather short on RAM, Chris Fenton has produced one of the most inspiring home projects around, coining the term “computational necromancy” along the way; a term which we hope to hear again sometime soon.